Rotary seat construction having novel bearing means therein



Oct. 23, 1962 F. LIE 3,059,888

ROTARY SEAT CONSTRUCTION HAVING NOVEL BEARING MEANS THEREIN Filed Feb.26, 1960 INVENTOR.

FINN LIE BY 46 45 v Wmsom, Lewls Mc EAE A TTORN EYS EJ315938 Un1tedStates Patent Office 0,. 23,1962

3,059,388 ROTARY SEAT CONSTRUCTIUN HAVING NOVEL BEARHNG MEANS TIEEREHNFinn Lie, Ring tation, near Hamar, Norway Filed Feb. 26, 196i), Ser. No.11,292 3 Claims. (Cl. 248-161) This invention relates to a seatconstruction, and particularly to a swivel seat construction and novelbearing mechanism for permitting free rotary movement of the seat andvertical adjustment thereof when desired.

In rotary seat constructions, and particularly in oflice chair seats, itis desirable that the seat be capable of easy swivelling motion withoutwobble or play such as would make the seat unstable or unsafe for theuser. Additionally the seat construction should be capable of readyvertical adjustment in accordance with the particular needs ofindividual users. The features of non-wobble action, easy rotatability,and ready vertical adjustment should be available in a constructionhaving relatively low cost so as to enable the complete assembly to besupplied competitively with other prior art structures.

With the above points in mind, it is a primary object of the inventionto provide a seat structure having improved features of low cost, easyrotatability, and rapid vertical adjustment.

A further object of the invention is to provide a seat constructionhaving a vertical adjustment structure which may be operated by astenographer or other persons having a minimum knowledge of mechanicalstructures.

It is an additional object of the invention to provide a rotary seatstructure having an improved novel bearing structure of long life andimproved anti-wobble construction.

Another objects of the invention is to provide a hearing structurehaving design features for incorporation of lubricant therein.

A further object of the invention is to provide a bearing structurehaving a relatively silent operation.

Another object of the invention is to provide a bearing structureadapted to handle radial and end thrust loads in a manner to prevent anywobble of the rotary element.

Other objects of this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a vertical sectional view taken through a chair constructionincorporating features of the present invention.

FIG. 2 is a sectional view taken on line 22 in FIG. 1.

Before explaining the present invention in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in theaccompanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways. Also,it is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation.

Referring to the drawing there is shown a chair construction including aconventional base structure 10, a conventional seat structure 12 havinga threaded spindle 14 carried therebeneath, and a novel mechanism 16 forrotatably 'adjustably mounting the seat structure and spindle structureon the base structure 10.

Base structure comprises a generally conventional leg structure 18.Structure 18 carries an upwardly opening steel tube 20 having a lowerend 22 and a flaring upper end 24 defining a general conical bearingsurface 26. The threaded spindle 14, provided with threads 14a extendsinto the tube 20 through a frustro-conical bearing element 30 having arelatively large annular end face 32 and a relatively small annular endface 34. The central opening 36 of bearing element 30 clears the threads14a. Element 3% is preferably formed of nylon or other plastic materialhaving good impact resistance and anti-friction properties.

The bearing element is prevented from having any rotation with respectto spindle 14 by means of a key extending into a groove 4G in thespindle 14.

Seated on the upper face 32 of element 30 is a nut 42 havingdiametrically opposite grooves '44 formed in its lower face to receiveprojections 46 formed on hearing element 30. if desired, additionalgrooves and projections could be provided between members 30' and 42 forensuring a locking action. The nut 42 is of course threaded on thespindle 14 the arrangement being such that when the occupant is seatedon the chair the assembly of elements 14, 3t} and 42 is keyed together;as a result the occupant is enabled to freely rotate the seat structurearound the axis of tube 2th. The bearing element 30 takes the end thrustas well as the radial thrust so as to cooperate with tube 20 inpreventing any wobble or play of the seat structure. In this manner theseat structure is confined to rotary motion, and the occupant feels asense of safety and ease which is not present with wobbly chairconstruction.

Conical surface 5i) of bearing element 30 is preferably provided with aseries of annular indentations or grooves 52 which have the effect ofpreventing squeaking noises such as are sometimes encountered withplastic bearing constructions. Additionally the grooves may receivegrease or other lubricant for further enhancing the selflubricatingqualities of the plastic bearing element material, the arrangement beingsuch as to provide a noiseless, long-life construction requiring aminimum of maintenance.

The long-life character of the construction is further enhanced by thefact that the bearing element is enclosed on its surfaces by the othercomponents so as to preclude any cold flow of the bearing plasticmaterial during application of heavy loads onto the seat structure.Thus, the upper face 32 of the bearing element 30 is engaged by thelower surface of the nut 42, the concal surface 5%] of the bearingelement 30 is completely encompassed by the flaring portion 24 of tube20, and the annular surface 36 of the bearing element is engaged by thesurface of spindle 14. The result is such that abnormal loads do notprovide any appreciable deformation or cold flow.

It will be noted from FIG. 2 that the bearing element 30 is providedwith a vertical slit 54. The purpose in this slit is to enable thebearing element 30 to change dimension circumferentially under load soas to make intimate bearing engagement with as much of the bearingsurface 26 as possible. This compensates for manufacturing inaccuraciesin forming the flare 24. The action is such as to provide an automaticcentering of the spindle relative to the axis of the tube 20 so as tocooperate with the tube in providing a smooth anti-friction, antiwobblearrangement. In this connection it will be noted that the spindle isaccurately guided at two widely spaced points, i.e., by element 30 andat the lower end portion of sleeve 20. The threads 14a are of slightlyless major diameter than the internal diameter of tube 2% in order toprevent wear.

It has been previously pointed out that seat structure 12 is preferablymounted for vertical adjustment relative to base structure 10. Inperforming the vertical adjust ment operation, seat structure 12 islifted so as to lift spindle 14 relative to the tube 20. The nut 42 ismeshed with the spindle threads 14a and it will accordingly be liftedwith the spindle 14. However, bearing element is somewhat looselyreceived on the spindle and the bearing element 30 may not lift with thespindle 14 from the tube 20, i.e., there may be a lowering of thebearing element 30 on the spindle 14 when the seat structure is lifted.When the spindle 14 is lifted nut 42 may be rotated on the spindle 14 toa new position of adjustment, either upwardly or downwardly from itsillustrated position. The seat structure can then be lowered, with thebearing element 30 seating on the conical bearing surface 26. If theprojections 46 do not register with recesses 44 the seat structure andspindle assembly can be rotated until the recesses drop down onto theprojections. Thereafter the projections serve to automatically lock thenut onto the bearing element 30. Since as previously noted, the bearingelement 30 is locked onto the spindle 14 by the lug-groove means 38, 40,the entire assembly of elements 12, 14, 30 and 42 is adapted forrotation relative to the base structure 10.

It is an object of the present invention to provide a rotaryseat-support arrangement having improved anti- Wobble action over arelatively long service life, and accordingly it is preferred toeliminate any steel-to-steel engagement of movable parts such as wouldcause ex cessive wear or noise. To eliminate such wear, particularly atthe lower end of the spindle, there may be provided one or more nylon orother plastic collars 39, each preferably having bevelled faces as at 41for defining grooves 43 to accommodate grease or other lubricant ifdesired.

The collars 39 may be provided with a lug (not shown) similar topreviously discussed lug 38, and the collars are secured against axialdisplacement along the spindle by any suitable means, as for examplepress fit, set screw means, or flanging of the spindle.

It vw'll be understood that use of collars 39 in combination withbearing 30 provides two spaced supports for the spindle. By thisarrangement there is a minimum tendency of the chair to wobble inservice. The pre ferred use of nylon or other plastic material forhearing 30 and collars 39 results in minimum Wear, long service life,and minimum noise. In some instances the plastic may give a slightsqueaking noise, and in order to counteract such noise the tube 20 maybe filled with grease, oil or other lubricant. A suitable closure 45 maybe provided on the lower end of tube 20 to retain the lubricant withinthe tube.

It will be seen that the illustrated construction is susceptible to verylow cost manufacture since a minimum number of component parts arerequired. In operation the elements have a smooth, trouble free movementwhich contributes materially to prolonged service life. It will \beunderstood that various modifications may be resorted to withoutdeparting from the spirit of the invention as defined in the appendedclaims.

I claim:

1. In a chair construction the combination comprising a base structuredefined by a vertical tube having a flaring upper end portion forming aconical bearing surface; an annular deformable bearing element having aconical face, said face being seated substantially entirely within saidbearing surface; a nut removably carried on said bearing element; meansbetween said bearing element and nut for preventing relative rotarymovement therebetween when the nut and bearing element are engaged withone another; a seat structure having spindle threaded into the nut andextending through the bearing element into the vertical tube; meansbetween the bearing element and spindle for preventing relative rotarymovement between the spindle and bearing element while permitting axialmovement of the spindle relative to the bearing element; the arrangementbetween the bearing element, nut and spindle being such that when thebearing element is pressed against the conical bearing surface thebearing element-nut-spindle assembly can be rotated as a unit relativeto the tube, but when the spindle is lifted relative to the tube the nutcan be disengaged from the bearing element and threaded along thespindle to a new position for establishing a vertical adjustment of thespindle and seat structure relative to the base structure.

2. In a chair construction the combination comprising a base structuredefining an annular upwardly flaring bearing surface; an annular plasticbearing element having an annular upwardly flaring face rotatably seatedon said bearing surface; a nut removably carried on said bearingelement; the spacing between the nut and the outermost portion of thebearing surface being such that the bearing element is substantiallycompletely enclosed by the nut and bearing surface to prevent cold flowof the plastic bearing element material; means between said bearingelement and nut for preventing relative rotary movement therebetweenwhen the nut and bearing element are engaged with one another; a seatstructure having a threaded spindle meshingly engaged with the nutthreads and extending through the bearing element; and means between thebearing element and spindle for restricting the spindle to axialmovement relative to the bearing element; the arrangement between thebearing element, nut and spindle being such that when the bearingelement is pressed against the bearing surface the bearingelement-nut-spindle assembly can be rotated as a unit relative to thebase structure, but when the spindle is lifted relative to the basestructure the nut can be disengaged from the bearing element andthreaded along the spindle to a new position for establishing a verticaladjustment of the spindle and seat structure relative to the basestructure.

3. An axially adjustable rotatable connection compris ing means formingan annular dish-shaped bearing surface; an annular bearing elementrotatably engaging said bearing surface; a nut removably engaged withsaid bearing element; means between said bearing element and nut forpreventing relative movement therebetween when the bearing element andnut are engaged with one another; a spindle threaded into the nut andextending through the bearing element; and means between said bearingelement and spindle for restricting said spindle to axial movementrelative to the bearing element; said bearing element having an axialslit therethrough to permit circumferential change of dimension of thebear ing element under change of axial load.

References Cited in the file of this patent UNITED STATES PATENTS504,460 Snider Sept. 5, 1893 682,844 Ellenbecker Sept. 17, 19011,332,200 Borgarello Mar. 2, 1920 1,937,892 Huntley Dec. 5, 19332,542,469 Bolens Feb. 20, 1951 2,561,102 Elleman July 17, 1951 2,742,082Lief Apr. 17, 1956 2,859,799 Moore Nov. 11, 1958 2,936,166 Wise May 10,1960 2,939,517 Saarinen June 7, 1960 FOREIGN PATENTS 800,885 GermanyJuly 8, 1949

